<https://www.srishtidigilife.co.in/ecommerce/product/relay-camera-coupler-crnpfz100-compatible-with-sony-a7iii-a7riii-a9/#product>
<http://schema.org/description>
"Relay Coupler is simply an insert for your camera battery cavity that enables powering the camera via Case Relay Camera Power System. The coupler does not contain a battery or hold a charge.\r\n \tCoupler cable is 10″ (25.4cm) – Coupler cable with Relay cable is 50″ (127cm)"
<https://www.srishtidigilife.co.in/ecommerce/product-category/tethering/accessories/>